There is an X-ray measuring instrument having an X-ray source and a two-dimensional detector disposed at the open ends of a support shaped like letter C (hereinafter referred to as a C-arm) so that the X-ray source and two-dimensional detector will be opposed to each other. There is a structure that suspends the C-arm from the ceiling or a structure that bears the C-arm on the floor. Moreover, there is an X-ray measuring instrument having the X-ray source and two-dimensional detector mounted in a gantry in such a manner that the X-ray source and two-dimensional detector are opposed to each other. In these instruments, while the pair of the X-ray source and detector is rotated about a subject by rotating the C-arm or gantry, X-ray measurement can be performed. Moreover, multiple measurement data items acquired during rotational measurement are corrected in order to produce a set of projection data items required for three-dimensional reconstruction. A three-dimensional reconstruction algorithm is used to perform reconstruction on the set of projection data items, whereby a three-dimensional image can be produced. The three-dimensional measurement is described in non-patent document 1.
Non-patent document 1: New Medicine, October 2002, Vol. 29, No. 10, pp. 102-105